Ventilation structure in exterior wall body

ABSTRACT

A ventilation structure in an exterior wall body incorporates: a pair of wooden column members erected spaced away from each other; a wooden beam member installed across on the pair of wooden column members and having a first ventilation groove at an exterior face; a wooden base member installed across lower ends of the pair of wooden column members and having a second ventilation groove at an exterior face; and a base plywood fixed to an exterior face of each of the pair of wooden column members, the wooden beam member, and the wooden base member, and serving as a base of a decorative exterior wall member, wherein a plurality of the first ventilation grooves and a plurality of the second ventilation grooves are formed away from each other in a horizontal direction.

TECHNICAL FIELD

The present invention relates to a ventilation structure in an exterior wall body.

BACKGROUND ART

In general, it is known that, in a building having a wooden structure, when internal dew condensation occurs in an exterior wall body, a framework and an exterior wall member corrode and a building main body is greatly damaged. This internal dew condensation occurs when moisture that has entered the inside of the exterior wall body is cooled in a case where the air temperature difference between the interior space and the exterior space increases. In the related art, there has been proposed a structure in which a ventilation layer is formed inside the exterior wall body to prevent internal dew condensation inside the exterior wall body. (For example, Patent Literature 1)

The structure described in Patent Literature 1 describes that a ventilation layer extending in the vertical direction is secured at the interior side relative to the exterior wall member serving as the finishing material. In this structure, air containing moisture in the ventilation layer flows from bottom to top by natural ventilation, and is discharged to the exterior space through a gap between the roof member and the exterior wall member. Therefore, moisture does not accumulate in the exterior wall body, and internal dew condensation in the exterior wall body can be effectively prevented.

CITATION LIST Patent Literature

-   Patent Literature 1: JP 8-312031 A

SUMMARY OF THE INVENTION Technical Problems

However, in the invention described in Patent Literature 1, in the exterior wall body, the ventilation layer is formed only at the exterior side, so that in a case where air containing moisture enters the interior space relative to the ventilation layer, such moisture is not discharged, and may corrode the framework such as the beam material and the interior wall member.

Therefore, the present invention has been made in view of the above-described problems, and an object thereof is to provide a ventilation structure in an exterior wall body capable of more effectively discharging moisture in the exterior wall body in a building having a wooden structure.

Solutions to the Problems

A ventilation structure in an exterior wall body of the present invention, the ventilation structure comprising: a pair of wooden column members erected spaced away from each other; a wooden beam member installed across on the pair of wooden column members and having a first ventilation groove at an exterior face; a wooden base member installed across lower ends of the pair of wooden column members and having a second ventilation groove at an exterior face; and a base plywood fixed to an exterior face of each of the pair of wooden column members, the wooden beam member, and the wooden base member, and serving as a base of a decorative exterior wall member, wherein a plurality of the first ventilation grooves and a plurality of the second ventilation grooves are formed away from each other in a horizontal direction.

The ventilation structure in the exterior wall body of the present invention, wherein an exterior face of the base plywood is away from an interior face of the decorative exterior wall member.

The ventilation structure in the exterior wall body of the present invention, further comprising: an intermediate column member erected between the pair of wooden column members; and a reinforcement plywood installed at an interior side relative to the base plywood and fixed to the intermediate column member, wherein the reinforcement plywood has an upper end installed spaced away from a lower end face of the wooden beam member, and a lower end installed spaced away from an upper end face of the wooden base member.

Advantageous Effects of Invention

According to the ventilation structure in the first exterior wall body of the present invention, the wooden beam member has a plurality of first ventilation grooves, at an exterior face, extending from an upper end to a lower end where the first ventilation grooves are away from each other in the horizontal direction, and the wooden base member has a plurality of second ventilation grooves, at an exterior face, extending from an upper end to a lower end where the second ventilation grooves are away from each other in the horizontal direction. Therefore, the air existing in the interior side relative to the base plywood in the exterior wall body flows from the bottom to the top through each ventilation groove by natural ventilation, so that it is possible to prevent stagnation of moisture and to effectively prevent corrosion of the wooden beam member and other wall members due to internal dew condensation.

According to the ventilation structure in the second exterior wall body of the present invention, since the exterior face of the base plywood is away from the interior face of the decorative exterior wall member, the ventilation layer is formed between the decorative exterior wall member and the base plywood. Therefore, the air existing in the exterior space relative to the base plywood in the exterior wall body flows from the bottom to the top through the ventilation layer by natural ventilation, so that it is possible to prevent stagnation of moisture and to effectively prevent corrosion of the base plywood or the decorative exterior wall member due to internal dew condensation.

According to the ventilation structure in the third exterior wall body of the present invention, the reinforcement plywood installed at the interior side relative to the base plywood and fixed to the intermediate column member has an upper end away from the lower end face of the wooden beam member and has a lower end away from the upper end face of the wooden base member. Therefore, it is possible to secure a ventilation passage of air existing in the interior side relative to the base plywood in the exterior wall body, and it is possible to effectively prevent the occurrence of internal dew condensation in the exterior wall body while constructing the exterior wall having high strength.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a horizontal cross-sectional view showing a ventilation structure in the first exterior wall body.

FIG. 2 is a cross-sectional view along line A-A of FIG. 1 .

FIG. 3 is a cross-sectional view along line B-B of FIG. 1 .

FIG. 4 is an enlarged cross-sectional view of part C in FIG. 3 .

FIG. 5 is an enlarged cross-sectional view of part D in FIG. 2 .

FIG. 6 is an enlarged cross-sectional view of part E in FIG. 2 .

FIG. 7 is a perspective view showing the state to fix a first base plywood.

FIG. 8 is a cross-sectional view showing a ventilation structure around the balcony.

FIG. 9 is a horizontal cross-sectional view showing a ventilation structure in the second exterior wall body.

FIG. 10 is a front view showing the state to be installed a vertical base member and a horizontal base member.

FIG. 11 is a front view showing the state to be installed a reinforcement plywood.

FIG. 12 is a cross-sectional view showing around a column leg part in a second exterior wall body.

FIG. 13 is a perspective view showing the state to fix a reinforcement plywood and a first base plywood.

DESCRIPTION OF EMBODIMENTS

Hereinafter, the best embodiment of the ventilation structure in the exterior wall body of the present invention will be described with reference to the drawings. The ventilation structure in the exterior wall body of the present application is for preventing internal dew condensation in the exterior wall body, and is mainly used in a detached house having a wooden structure, but may be used in other buildings as long as the structure is a wooden structure. In the present embodiment, a case where the ventilation structure in the exterior wall body is used around the first floor exterior wall of a detached house will be described. The “base plywood” in the present invention corresponds to a “first base plywood 61” in the present embodiment.

First Embodiment

A ventilation structure 1 in a first exterior wall body illustrated in FIGS. 1 and 2 is a structure for ensuring ventilation in a first exterior wall W1 which is a first floor exterior wall of a detached house. As illustrated in FIGS. 1 to 3 , the ventilation structure 1 in the exterior wall body includes a pair of wooden column members 2 erected spaced away from each other, a wooden beam member 3 installed across on the pair of wooden column members 2, a wooden base member 4 installed across lower ends 2 a of a pair of wooden column member 2, and a first base plywood 61 fixed at the exterior side relative to the pair of wooden column members 2, the wooden beam member 3, and the wooden base member 4, and serving as a base of a decorative exterior wall member 5.

The wooden column member 2 illustrated in FIGS. 1, 3, and 4 is a structural member erected on a building foundation 7, and includes a prismatic vertical member 21 extending in a vertical direction, and a column leg member 22 fixed to the lower end of the vertical member 21. The cross sectional dimension of the vertical member 21 is determined depending on the scale of the detached house, and has a face width and a depth length in a range of about 100 mm to 150 mm. As illustrated in FIG. 4 , the column leg member 22 includes a first plate 22 a placed on the building foundation 7, a second plate 22 b located above the first plate 22 a, and contacting a lower end face 21 a of the vertical member 21, a third plate 22 c extending upward from the second plate 22 b, and a cross coupling member 22 d that couples the first plate 22 a and the second plate 22 b. The first plate 22 a is fixed to the building foundation 7 by an anchor bolt 8, the third plate 22 c is fitted into an insertion groove (not shown) extending upward from the lower end face 21 a of the vertical member 21, and is fixed to the vertical member 21 by driving a nail 11 from an exterior face 21 c (see FIG. 1 ) of the vertical member 21. A height H1 from an upper end face 7 a of the building foundation 7 to an upper end face 22 e of the second plate 22 b is about 40 mm to 60 mm.

The distance between the pair of wooden column members 2 is determined by the position where the wooden column members 2 are disposed and the shape of the detached house, but is adjusted so that the center-to-center distance between the pair of wooden column members 2 is within a range of about 500 mm to 2000 mm. When the center-to-center distance between the pair of wooden column members 2 is large, as illustrated in FIG. 3 , stud column members 9 are erected at a predetermined interval between the pair of wooden column members 2. In the present embodiment, a case where the center-to-center distance between the pair of wooden column members 2 is 2000 mm will be described.

The wooden beam member 3 illustrated in FIGS. 3 and 5 is a structural member extending in the horizontal direction, and the depth length thereof is substantially the same as the depth length of the wooden column member 2. In addition, the wooden beam member 3 has a first fitting groove 31 extending from an exterior end edge to an interior end edge at a lower end face 3 a, and has a first ventilation groove 32 extending from an upper end 3 c to a lower end 3 d at an exterior face 3 b. The first fitting groove 31 is a groove for fitting the upper end of the stud column member 9 described above, and is formed at a position where the stud column member 9 is installed. The plurality of the first ventilation grooves 32 is away from each other at intervals of about 500 mm in the horizontal direction, and are formed at positions where the first fitting grooves 31 are avoided. The first fitting groove 31 and the first ventilation groove 32 each have a groove depth of about 10 mm to 15 mm, and the first fitting groove 31 is formed to have a width dimension substantially same as the face width of the stud column member 9 which is fitted, and the first ventilation groove 32 is formed to have a width in a range of about 30 mm to 35 mm.

The wooden base member 4 illustrated in FIGS. 3, 4, and 6 is a horizontal member that fixes the lower end of the stud column member 9 and the lower end of the first base plywood 61, and has a length substantially same as the distance between the pair of wooden column members 2, and has a depth length substantially same as the depth length of the wooden column member 2. In addition, the wooden base member 4 has a second fitting groove 41 extending from an exterior end edge to an interior end edge at an upper end face 4 a, and a second ventilation groove 42 extending from an upper end 4 c to a lower end 4 d at the exterior face 4 b. The second fitting groove 41 is a groove for fitting the lower end of the stud column member 9, and is formed at a position where the stud column member 9 is installed as in the first fitting groove 31. As in the first ventilation grooves 32, the plurality of the second ventilation grooves 42 is away from each other in the horizontal direction, and is formed at positions where the second fitting grooves 41 are avoided. The second fitting groove 41 has a groove depth and a width similar to those of the first fitting groove 31, and the second ventilation groove 42 has a groove depth, a width, and a distance from the adjacent second ventilation groove 42 similar to those of the first ventilation groove 32.

The first base plywood 61 illustrated in FIGS. 2 and 7 is a plate member installed at the exterior side relative to the wooden column member 2, the wooden beam member 3, and the wooden base member 4. The first base plywood 61 is made of structural plywood, particle board, or the like having excellent shear performance, and is formed to have a thickness of about 9 to 15 mm and a width of about 900 to 1000 mm. The height of the first base plywood 61 is adjusted by the height of a first floor of a detached house, and is formed in a range of about 2440 mm to 3030 mm.

The plurality of stud column members 9 illustrated in FIGS. 3 and 7 each is a vertical member installed to maintain the strength of the wall, and is installed away from each other in the horizontal direction, and the first base plywood 61 is fixed to the stud column member 9 with nails as in the wooden base member 4. The face width of the stud column member 9 is about 40 mm to 50 mm, and the depth length thereof is substantially the same as that of the wooden column member 2. Further, the distance between the adjacent stud column members 9 is about 450 mm to 500 mm.

Next, a construction method of the ventilation structure 1 in the first exterior wall body will be described. First, as illustrated in FIG. 4 , the first plate 22 a of the wooden column member 2 is inserted into the anchor bolt 8 protruding upward from the upper end face 7 a of the building foundation 7 and tightened with nuts 81, and the column member 2 is installed at a predetermined position on the building foundation 7. Then, as illustrated in FIG. 3 , in a state where the first ventilation groove 32 faces the exterior, the wooden beam member 3 is installed across on the pair of wooden column members 2, and the pair of wooden column members 2 and the wooden beam member 3 are connected by a predetermined joint fitting.

Next, as illustrated in FIGS. 3 and 4 , the wooden base member 4 is installed across at the lower ends of the pair of wooden column members 2. The wooden base member 4 is installed such that the lower end face 4 e has substantially the same height as the lower end face 21 a of the vertical member 21 with the second ventilation groove 42 facing the exterior. At this time, when a spacer (not shown) having a height as same the height H1 from an upper end face 7 a of the building foundation 7 to an upper end face 22 e of the second plate 22 b is placed on the building foundation 7 located below the wooden base member 4, the wooden base member 4 can be easily installed at a predetermined height. As illustrated in FIG. 4 , the wooden base member 4 installed at the predetermined position is connected and fixed to the wooden column member 2 when a corner of an L-shaped fitting 10 contacts a corner formed by the upper end face 4 a of the wooden base member 4 and a side face 21 b, of the vertical member 21, toward the wooden base member 4, and the nail 11 is driven in from above or from the side of the L-shaped fitting 10. In this way, when the wooden base member 4 is away from the building foundation 7, ventilation under the floor can be secured.

Subsequently, as illustrated in FIG. 3 , the upper end of the stud column member 9 is fitted into the first fitting groove 31 of the wooden beam member 3, and the lower end of the stud column member 9 is fitted into the second fitting groove 41 of the wooden base member 4. Then, the nail (not shown) is driven in an obliquely upward direction from the side of the upper end of the stud column member 9, and the nail (not shown) is driven in an obliquely downward direction from the side of the lower end of the stud column member 9 to fix the stud column member 9 to the wooden beam member 3 and the wooden base member 4. Next, as illustrated in FIG. 6 , a draining member 12 extending in the longitudinal direction of the wooden base member 4 is screwed to the lower end of the exterior face 4 b of the wooden base member 4. As illustrated in the figure, the draining member 12 protrudes in the exterior direction such that the exterior end edge thereof is away from the building foundation 7, and can flow downward rainwater passing the decorative exterior wall member 5.

Then, as illustrated in FIGS. 1 and 2 , the first base plywood 61 is fixed to of the pair of wooden column members 2, the wooden beam member 3, and the wooden base member 4 at the exterior side. As illustrated in FIG. 7 , the first base plywood 61 has a peripheral edge and a substantially central portion in a width direction fixed to the exterior face 21 c of the vertical member 21, the exterior face 3 b of the wooden beam member 3, the exterior face 4 b of the wooden base member 4, and the exterior face 9 a of the stud column member 9 with the nails 11. As illustrated in FIGS. 1 and 2 , a second base plywood 62 made of a material and a shape similar to those of the first base plywood 61 is fixed to the interior faces of the wooden column member 2, the wooden beam member 3, the wooden base member 4, and the stud column member 9. Finally, the plate-shaped decorative exterior wall member 5 is fixed to the first base plywood 61 at the exterior side with a dedicated metal fitting (not illustrated) to form the first exterior wall W1, and the ventilation structure 1 in the first exterior wall body is completed. At this time, as illustrated in FIGS. 5 and 6 , an exterior face 61 a of the first base plywood 61 is away from an interior face 5 a of the decorative exterior wall member 5 to form a gap S between the first base plywood 61 and the decorative exterior wall member 5. Since the decorative exterior wall member 5 is installed so that the lower end 5 b thereof is away from the draining member 12, exterior air can enter the gap S from the lower end 5 b of the decorative exterior wall member 5.

The air around the lower end of the first exterior wall W1 formed in this manner passes through the inside of the first exterior wall W1 by the upward airflow and moves upward. That is, the air existing below the draining member 12 illustrated in FIG. 6 passes through the second ventilation groove 42 of the wooden base member 4 and the first ventilation groove 32 of the wooden beam member 3 in this order from between the draining member 12 and the building foundation 7 as shown by an arrow X1 in FIG. 3 , and moves upward. Further, the air around the lower end of the decorative exterior wall member 5 passes through the gap S from between the lower end 5 b of the decorative exterior wall member 5 and the draining member 12 and moves upward as indicated by an arrow Y in FIGS. 5 and 6 .

The air thus moved upward can be discharged to the exterior from an eaves back ventilation port D1 illustrated in FIG. 8 , a hut back ventilation port (not illustrated), and the like. Also shown, in a case where a balcony T is formed in the detached house, by providing a ventilation cutout Tb in a floor base plywood Ta located in the peripheral edge of the balcony T, the air in an eaves back space S2 passes through the inside of a waist wall Wa erected on the outer peripheral portion of the balcony T, and is discharged to the exterior through a gap between a coping Wb installed at the upper end of the waist wall Wa and a decorative waist wall member We of the waist wall Wa (see an arrow Z in FIG. 8 ).

Thus, the ventilation structure 1 in the exterior wall body of the present application forms not only a ventilation layer between the first base plywood 61 and the decorative exterior wall member 5, but also a ventilation passage in a portion surrounded by the first base plywood 61 and the second base plywood 62, so that even when air containing moisture enters the interior space in the first exterior wall W1, the moisture can be discharged to prevent corrosion of the framework such as the wooden beam member 3 and the interior wall member.

Second Embodiment

Next, a ventilation structure 13 in a second exterior wall body will be described with reference to the drawings. The second embodiment has substantially the same configuration as that of the first embodiment except that the configuration of the intermediate column member and the reinforcement plywood is different from that of the first embodiment. Therefore, the same reference numerals are given to the same configurations as those of the first embodiment, and the description thereof will be omitted. The ventilation structure 13 in the second exterior wall body illustrated in FIG. 9 is a structure for securing ventilation in a second exterior wall W2 used for the first floor of a detached house, and the second exterior wall W2 is used for a portion requiring higher strength in the exterior wall of the detached house. As illustrated in FIGS. 9 and 10 , the ventilation structure 13 in the second exterior wall body includes a pair of wooden column members 2, a wooden beam member 3, a wooden base member 4, a first base plywood 61, an intermediate column member 14 erected between the pair of wooden column members 2, and a reinforcement plywood 15 installed at the interior side relative to the first base plywood 61, and fixed to the intermediate column member 14.

The plurality of intermediate column members 14 illustrated in FIGS. 10 and 13 each is a vertical member installed to maintain the strength of the wall as in the stud column member 9, and is installed away from each other in the horizontal direction. In the present embodiment in which the distance between the adjacent intermediate column members 14 is about 450 mm to 500 mm, and the center-to-center distance between the pair of wooden column members 2 is 2000 mm, three intermediate column members 14 are installed as illustrated in the figure. Among them, the intermediate column member 14 installed substantially at the center between the pair of wooden column members 2 has a face width of about 40 mm to 50 mm and a depth length similar to that of the wooden column member 2, and the other two intermediate column members 14 are formed to have a face width of about 40 mm to 50 mm and a depth length shorter than that of the wooden column member 2 by the thickness of the reinforcement plywood 15. As illustrated in FIG. 10 , the upper end of the intermediate column member 14 is fitted into the first fitting groove 31 of the wooden beam member 3, and the lower end thereof is fitted into the second fitting groove 41 of the wooden base member 4. That is, in the present embodiment, the first fitting groove 31 and the second fitting groove 41 are formed at positions where the intermediate column member 14 is installed.

The reinforcement plywood 15 illustrated in FIG. 13 is a plate member installed between the intermediate column member 14 installed substantially at the center between the pair of wooden column members 2 described above and the wooden column members 2. As in the first base plywood 61, the reinforcement plywood 15 is made of structural plywood, particle board, or the like having excellent shear performance, and is formed to have a thickness of about 9 to 15 mm and a width of about 900 to 1000 mm. The height of the reinforcement plywood 15 varies depending on the height of the first floor of the detached house, but is formed at least at a height shorter by about 20 mm than the height from the lower end face 3 a of the wooden beam member 3 to the upper end face 4 a of the wooden base member 4.

The reinforcement plywood 15 can be fixed to a vertical base member 16 extending in the vertical direction and a horizontal base member 17 extending in the horizontal direction illustrated in FIG. 10 . The vertical base member 16 is formed to have a height substantially equal to the height from the lower end face 3 a of the wooden beam member 3 to the upper end face 4 a of the wooden base member 4, and is formed to have a face width of about 40 mm to 50 mm and a depth length shorter than that of the wooden column member 2 by the thickness of the reinforcement plywood 15. Further, the horizontal base member 17 is a member installed between the wooden column member 2 and the intermediate column member 14 or between the adjacent intermediate column members 14, and is formed to have a length of about 340 mm to 370 mm and a height of about 40 mm to 50 mm, and the depth length is substantially the same as that of the vertical base member 16.

Next, a construction method of the ventilation structure 13 in the second exterior wall body will be described. First, according to the same procedure as that of the first embodiment, the wooden column member 2 is installed at a predetermined position on the building foundation 7, the wooden beam member 3 is installed on the pair of wooden column members 2, and the wooden base member 4 is installed across on the lower ends 2 a of the pair of wooden column members 2. Subsequently, as illustrated in FIG. 10 , the upper end of the intermediate column member 14 is fitted into the first fitting groove 31 of the wooden beam member 3, and the lower end of the intermediate column member 14 is fitted into the second fitting groove 41 of the wooden base member 4. At this time, as illustrated in FIG. 9 , the plurality of intermediate column members 14 is installed toward the interior side such that the interior face is located at substantially the same position as the interior face of the wooden column member 2 in plan view. Then, as in the stud column member 9, the nail (not shown) is driven in an oblique direction from the side of the upper end of the intermediate column member 14 or the side of the lower end of the intermediate column member 14, and the intermediate column member 14 is fixed to the wooden beam member 3 and the wooden base member 4.

Next, as illustrated in FIG. 10 , the vertical base member 16 is fixed at a predetermined position. That is, the vertical base member 16 is erected on the side of each of the wooden column members 2 toward the intermediate column member 14 and on both sides of the intermediate column member 14 located substantially at the center between the pair of wooden column members 2, and fixed to the wooden column members 2 and the intermediate column member 14 with the nail (not shown). Subsequently, the horizontal base member 17 is disposed between the vertical base member 16 and the intermediate column member 14 on the upper end face 4 a of the wooden base member 4, and the nail (not shown) is driven in from above to be fixed to the wooden base member 4. Further, the horizontal base member 17 is disposed between the vertical base member 16 and the intermediate column member 14 on the lower end face 3 a of the wooden beam member 3, and the nail (not shown) is driven in from below to be fixed to the wooden beam member 3. At this time, as illustrated in FIG. 9 , the vertical base member 16 and the horizontal base member 17 are installed toward the interior side such that the interior face is substantially the same position as the interior face of the wooden column member 2 in plan view. As illustrated in FIG. 10 , the horizontal base member 17 is fixed in a state where both ends are away from the intermediate column member 14 and the vertical base member 16.

Subsequently, as illustrated in FIGS. 9 and 13 , the reinforcement plywood 15 is fitted between the intermediate column member 14 installed substantially at the center between the pair of wooden column members 2 and the wooden column member 2, and fixed to the vertical base member 16, the horizontal base member 17, and the intermediate column member 14 with the nail 11. At this time, as illustrated in FIG. 11 , the reinforcement plywood 15 is installed so that an upper end 15 a is away from the lower end face 3 a of the wooden beam member 3 by about 10 mm and a lower end 15 b is away from the upper end face 4 a of the wooden base member 4 by about 10 mm.

Then, in the same procedure as in the first embodiment, the draining member 12 is fixed to the lower end of the exterior face 4 b of the wooden base member 4 by a screw illustrated in FIG. 12 , and the first base plywood 61 and the second base plywood 62 are fixed to the pair of wooden column members 2, the wooden beam member 3, and the wooden base member 4. Finally, the decorative exterior wall member 5 is fixed to the first base plywood 61 at the exterior side with a dedicated metal fitting (not illustrated) to form the second exterior wall W2, and the ventilation structure 13 in the second exterior wall body is completed.

The air around the lower end of the second exterior wall W2 formed in this manner passes through the inside of the second exterior wall W2 by the upward airflow and moves upward. That is, as indicated by an arrow X2 in FIGS. 11 and 12 , the air existing around the wooden base member 4 passes through the second ventilation groove 42 of the wooden base member 4 from between the draining member 12 and the building foundation 7, then passes through between the wooden base member 4 and the reinforcement plywood 15, and between the horizontal base member 17 and the vertical base member 16 or the intermediate column member 14 in this order, and move in an upward direction. Then, the air passes between the wooden beam member 3 and the reinforcement plywood 15, passes through the first ventilation groove 32 of the wooden beam member 3, moves upward, and can be discharged to the exterior from the eaves back ventilation port D1 described above, a hut back ventilation port (not illustrated), and the like. Further, the air around the lower end of the decorative exterior wall member 5 is discharged to the exterior through the same ventilation passage as in the first embodiment.

The strength of the second exterior wall W2 formed in this manner can be further increased as compared with that of the first exterior wall W1 on which the reinforcement plywood 15 is not installed. Further, the depth lengths and the installation positions of the intermediate column member 14, the vertical base member 16, and the horizontal base member 17 are adjusted, the reinforcement plywood 15 is away from the wooden beam member 3 and the wooden base member 4, so that an air passage can be ensured, and moisture can be discharged from above. Therefore, the ventilation structure 13 in the second exterior wall body of the present application can effectively prevent the occurrence of internal dew condensation in the second exterior wall W2 while constructing an exterior wall structure with high strength.

The embodiment of the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the scope of the idea of the present invention.

INDUSTRIAL APPLICABILITY

The ventilation structure in the exterior wall body according to the present invention can be suitably used for a building having a wooden structure, and can be used for securing ventilation from the eaves back to the upper floor.

DESCRIPTION OF REFERENCE SIGNS

-   1 ventilation structure in an exterior wall body -   2 wooden column member -   2 a lower ends of wooden column member -   21 a exterior face of vertical member (exterior face of wooden     column member) -   3 wooden beam member -   32 first ventilation groove -   3 a lower end face of wooden beam member -   3 b exterior face of wooden beam member -   3 c upper end at exterior face of wooden beam member -   3 d lower end at exterior face of wooden beam member -   4 wooden base member -   42 second ventilation groove -   4 a upper end face of wooden base member -   4 b exterior face of wooden base member -   4 c upper end at the exterior face of wooden base member -   4 d lower end at the exterior face of wooden base member -   5 decorative exterior wall member -   5 a interior face of decorative exterior wall member -   61 first base plywood -   61 a exterior face of first base plywood -   13 ventilation structure in second exterior wall body -   14 intermediate column member -   15 reinforcement plywood -   15 a upper end of reinforcement plywood -   15 b lower end of reinforcement plywood 

1. A ventilation structure in an exterior wall body, the ventilation structure comprising: a pair of wooden column members erected spaced away from each other; a wooden beam member installed across on the pair of wooden column members and having a first ventilation groove at an exterior face; a wooden base member installed across lower ends of the pair of wooden column members and having a second ventilation groove at an exterior face; and a base plywood fixed to an exterior face of each of the pair of wooden column members, the wooden beam member, and the wooden base member, and serving as a base of a decorative exterior wall member, wherein a plurality of the first ventilation grooves and a plurality of the second ventilation grooves are formed away from each other in a horizontal direction.
 2. The ventilation structure in the exterior wall body according to claim 1, wherein an exterior face of the base plywood is away from an interior face of the decorative exterior wall member.
 3. The ventilation structure in the exterior wall body according to claim 2, further comprising: an intermediate column member erected between the pair of wooden column members; and a reinforcement plywood installed at an interior side relative to the base plywood and fixed to the intermediate column member, wherein the reinforcement plywood has an upper end installed spaced away from a lower end face of the wooden beam member, and a lower end installed spaced away from an upper end face of the wooden base member. 